Scleroscope



Feb. 6, 192s. 4,444,607. -v R. HERRMANN.

SCLEROSCOPB ORIGINAL FILED IULY28, |920. 2 SHEETS-SHEET I.

OMI

R. HERRMANN. SCLERO'SCOPE. ORIGINAL FILED JULY 28, 1920. 2 SHEETS-SHEET 2.

Feb. 6, 192s. 1,444,607.

Patented Feb. 6, i923.

. nutren erratas RICHARD EERBMANN', OF BERLIN, GERMANY, ASSIGNOR T0 SCHUCKABDT it SCHTTE,

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0F BERLIN, GERMANY, A FIRM.

SCLEROSCOPE.

Original application filed July 28, 192D, Serial No. 399,645.

To all whom t may concern:

Be it lrnown that l,'PtroHARo l-l'nRRMANN, a citizen of Germany, and resident ot Berlin, in the .State or" Prussia, German Empire, have invented certain new and useful l'niprovements in Scleroscopes, of which the following is a specification.

The invention relates to a scleroscope or apparatus tor testing the hardness ot solid bodies, more particularly metals, by means of a falling weight.

lt has already been suggested for scleroscopes to guide a dropping weight or hammer provided with a hard point, in glass tube provided with graduatio-ns, and to return it to the top ot the tube .by pneumatic means into a device for catching' and retaining it. Owingto the use ot pneumatic means, the glass tube had to be closed up, so that its wall between the scale marked. on the outside oi' the glass tube and the weight formed an obstacle to the enact reading of the scale. Errors in reading were likely to be'caused owing to reiiectiou or refraction.

Moreover the glass tube is very fragile. The pneumatic device used for returning the weight into the catching device, was constituted in these instruments by a rubber ball and tube. lt easily became leaky, and moreover, rubber cannot always be obtained oi the desired quality, and is a comparatively expensive material.

This invention relates to a scleroscope in which the weight slides in a preterably metal guide. For returning the weight to its original position a mechanical springoperated driver is used.

The guide track for the falling weight or hammer is in the apparatus according to the invention or' prismatie shape and preierably made practically three-sided and covered on the open side with glass or some other transparent material, owing to which it is prevented from becoming,` dirty. rl`he hammer engages its guide only along` lines, so that the engaging surfaces are kept clean by the hammer, and air can move freely past the falling hammer through the corners ot the prism. ln this way, the height oi? rebound ci' the hammer is increased by more than l0% compared to the older devices,

and therefore the accuracy oit' measurements is correspondingly increased. The device returning' the 'Selling hammer to its original position is carried by means oic an extension through a corner of the `Lguide prism, so that the l.guide tor the hummer is continuous throughout the whole oi' its length, and no lateral deviation ci the falling hammer. which would aiiect the accuracy, can taire place.

The release ot the hammer and the operation ot the returning device taire placeA peri'ectly independently of each other. that way, when the hammer is released, the comparatively powerful returning; spring need not be compressed, and the releasing device can be operated by a very slight pressure oi the linger, so that there is no risl oi. forcing the device out oit its vertical position when oper-ruting it without supports.

liioreover. the returning device is so constructed that when it operated, the returning part is automatically released by a stop, after the returning; spring` has been compressed by the niioveinent ,ot a sprintfeontrl'illed rod, flglfter the return, the returningdevice .'n comes into enga-gement with its operating` device. i

ln the accompanying drawings:

Fig'. 1 is a vertical longitudinal section showing a construction ot the apparatus in the position of rest.

Fig'. Q is la vertical longitudinal section through the apparatus at the moment ot release oi the returning device. The highest position of the returning` device betere it reachesthe position et rest, is shown in dotted lines.

Fig'. 3 is a cross-section on the line A-B ot Fig. l, and

e `is cross-section on the line Cf--D oi Fig. i2..

Similar characters oi reierence designate. corresponding' parts throughout the several views.

ln the construction shown, in the front of the body d oi' the apparatus is arranged a prismatic, preferably three-sided guide "lor the hammer a, which is covered in iront by a strip ot glass ll. rlhe glass strip ll is arranged in a groove ci the body Z and held at the top and at the bottom by covering IDivided and this application filed August 18, Serial No. 493,460.

plates 16 and 16. On the upper end of the body 0l is mounted a head 31 in which above the guide 10 are pivoted about a pin 13 two catches or hooks 5. The catches are provided at the top with projections Z9 and 792. Against the projections b is pressed by a spring 141 -a sleevew3 2 which has a hollow conical surface at the bottom. The projections Z2 are thus moved inwards towards each other and the hooked bottom ends of the catches, which engage with a hollow space or 'recess ot the hammer, are spread out 1). The said sleeve 32 is surrounded by a pressure sleeve 33 which is adjustably mounted in the head 31. 1t is pressed upwards by the action ot the spring 14 until its projection engages with a corresponding projection of the bore. The pressure sleeve 33 has at vthe bottom an also hollow conical surface with which the catches engage with their lateral projections b2. If the sleeve 83 is pressed downwards in opposition to the action of the spring 14C, its hollow conical surface will move the catches in the direction opposite to that in which they are moved by the sleeve 32, and the hooked bottom ends of the catches are moved towards each other, until their hook-shaped ends are disengaged from the hammer so that the latter is released and drops (Fig. 2).

1n the head 31 is guided also the upper end `of the rod c operating the returning device. 'lts lower thin end engages with the groove 17 in the rear part of the body (Y. It is moved upwards by the spring 24 until it strikes by means of a collar 34 against the bottom surface or' the head 31.

The bottom end ot the pressure rod c which is guided in the projections 18 and 182 of the rear covering plate 18 of the apparatus, rests on a projection g at the lower end of the returning` device 7L which at its upper end is provided with an annular projection i which loosely surrounds the rod c. Between the said annular projection and the projection 182 of the rear covering plate is arranged the returning spring e. 1t presses the returning device upwards so that it strikes with a cam face the upper edge 22 of theslot 22 through which the returning device passes into the hammer guide. 1n this way the projection g of the returning member is held fast under the rod c. rEhe project-ion g of the returning member is also provided with a cam tace 36, and a further cam tace 37 is arranged on a projection at the bottom end oi? the rear covering plate 18.

The operation of the apparatus is as iollows:

On the rod c being depressed. it actson the projection g 0.1"' the returning device and drives the latter down, ythe spring e between the yprojection v', and the projection 182 being compressed. As soon as the cam 'face 36 of the projection g strikes the cam face 37, these two -faces slide on each other, and the bottom end or the returning device is forced aside, transversely to its direction of movement, and through the slot 22 into the path of the hammer', until the projection 28 of the returning device engages imder the hammer, and the projection g slides oli" the. lower end ot' the rod c and thus becomesl free (Fig. 2). r1`he returning device is then projected upwardly, by the expanding spring e and slides along the rod c, 1n this way, during the whole of the upward movement, the driver 23 of the returning device is positively guided in zthe guide of the hammer a and drives the latter upwardly. yis the rear tace of the projection g engages with the rod c, the lower end ot the returning` device at first remains in the position in which the driver 23 projects into the path of tall of the hammer. @n the lrod c being then released, it is again raised by the spring`24 until the collar 34A engages with the head 31. 1n that way the projection g of the returning device is released by .the lower end of the rod c, so that the spring e forces thel returning device still further upwards. The cam face 35 slides during that movement on the edge 22', owing to which the returning device is sent back again to the position fot rest in which the projection g engages under the lowerend ot the rod c. Thereturning device is now outside the path ot the ham.- mer a and the apparatus is ready to be used again.

.lt will be seen that in this construction the hammer can be easily removed trom ythe `guide after removing a stop pin 39 which is intended to prevent it `accidentally :falling out.

The present application is a division rof my coi-pending Yapplication Eierial No. 399,645, filed Juiy 2S, 1920.

1 claim:

1. In a scleroscope: the combination with a hammer adapted to be released, -mea-ns for normally holding the hammer v`and a casing; of a returning device movable in the casing and adapted to engage therewith to be released; and resilient means to `actuate said returning device.

- 2. 1n a scleroscope: the combination with a hammer adapted Vto be released, means for normally holding the hammer and a casing; ot' a returning device movable in the casing and adapted to engage therewith to be released; a returning spring compressible by the returning device; and a spring controlled rod to move the returningdevice to effect compression of its said returning spring and to effect its release. I

B. 1n a scleroscope: the combination with a hammer adapted to be released, means for normally holding the hammer and a casing; oa returning device movable downwardly in the casing and transversely thereto thru engagement therewith; and resilient means to actuate said returning device.

4. ln a scleroscope: the combination with a hammer; adapted to be released; means :for normally holding the hammer and a casing; of a returning device movable downwardly in the casing and transversely thereto thru engagement therewith; a returning spring compressible by the returning device; and a spring controlled rod to move the return ing device to effect compression of its said spring and to etl'ect its release.

In a scleroscope: the combination with a hammer; adapted to be released; and means for normally holding the hammer of a returning device; a spring adapted to be compressed thereby; a spring controlled rod to eiieet the compression of the said returning spring; a projection on the lower end of said lreturning device and upon which said rod rests, said returning device being longitudinally and transversely movable; and a projection adapted to engage with the said projection ot the returning device and force the latter aside in its lowest position to thereby release its compressed spring.

G. ln a scleroscope: the combination with a hammer; adapted to be released, and means for normally holding the hammer of a returning device; a projection thereon having a cam tace; a casing having a cam face, said came faces being adapted to strike each other in the lowest position ofY the returning device to release the latter.

7. in a scleroscope: the combination with a hammer; adapted to be released, means for normally holding the hammer and a casing; ci" a returning device movable downwardly in the casing and adapted to engage therewith to be released; a projection on said returning device; a'releasing rod adapted to rest on said projection; and a stop on said casing to return the said projection over the releasing rod when the returning device 'has reached its highest position.

8. ln a scleroscope: the combination with hammer; adapted to be released; and means for normally holding the hammer of a returning device; a projection having a cam face thereon; a releasing rod resting upon said cam face and a slot; the projection being adapted to strike the upper edge oit the guide slot oi the casing and to slide along said edge to guide the returning de vice with its projection and cam face under the rod.

9. ln a scleroscope: the combination with a hammer; adapted to he released; and means Yroi' normally holding the hammer or a returning device; a projection Vifrom saine having a cam face thereon; a casing having a cani face and a slot;` said cam faces being adapted to strike each other in the lowest position ot the returning device to release the latter; a spring adapted to be compressed by the returning device; a spring controlled releasing rod resting upon the cam tace of the returning device to eect the compression of the said returning spring; the returning device being longitudinally and transversely movable and forced aside in its lowest position to release its compressed sprin by the engagement or the cam tace oi" its projection with the cam face el the casing. and its said projection being adapted to strike the upper edge of the guide slot ot the casing' and to slide along' said edge to guide the returning device with its projection and cam 'tace under the releasing rod.

Signed at Berlin in the State ofi Prussia, .terman Empire, this 29th day oi July A. l). 192i.

RICHARD HERRLANN.

TLWitnesses:

GEORGE Binner; JOHANNES Ferran. 

